1. Field of the Invention
The present invention relates to flooring systems and methods. More specifically, the present invention relates to a raised access floor having removable panels with a high strength-to-weight ratio.
2. Description of Related Art
There are a wide variety of environments in which it may be desirable to store items such as fluid conduits, electrical wiring, machinery, or the like underneath a floor. Hence, many offices and manufacturing facilities use a dual flooring system, in which a raised access floor is suspended above a support surface. The raised access floor may have a pattern of removable tiles or panels that permit relatively easy access to the items between the support surface and the raised access floor.
Known raised access floors are limited in a number of respects. For example, many raised access floors have comparatively low limitations regarding how much weight can be disposed over each panel. Thus, relatively heavy equipment cannot be stored without using a heavy duty panel. Heavy duty panels may be formed of die cast steel or the like, and are typically quite heavy. Consequently, they are difficult to lift for removal or replacement, and thus impede access to the space underneath the raised access floor. Some heavy duty panels are still unable to provide a sufficient load bearing capacity without exceeding OSHA standards for weights to be lifted manually.
Furthermore, many known panels for raised access floors are subject to brittle failure. Such panels may show little strain until failure; thus, failure is catastrophic and occurs without warning. Brittleness also provides a panel with a comparatively low toughness, or impact strength. Thus, if a relatively heavy object is dropped onto the panel, breakage or weakening of the panel may result.
Furthermore, many known panels can only be produced in one size and shape. Use of die casting or similar manufacturing methods provides a shape that cannot easily be modified without compromising the structural integrity of the shape. Consequently, panels of odd sizes or panels with openings to provide wire or conduit passage, or the like, cannot easily be made, and, if cut from an existing cast panel, may not be sturdy enough for use in the environment.
Yet further, many known panels require enormous fixed costs to produce. A die cast raised access floor panel, for example, may require an initial investment of more than half a million dollars for fabrication of the die and related equipment. The die cannot readily be modified; hence, any alterations to the design of the panel will likely require a capital expenditure of the same magnitude.
Additionally, many known raised access floor systems require the fabrication and installation of a metal framework to support the panels. This is because some panels do not have sufficient edge strength to prevent deformation at the junctures between the panels. Consequently, each panel edge must be supported by a beam, or “stringer.” This also raises the cost and installation difficulty of the raised access floor, and severely impedes access to the space underneath the raised access floor because the framework is not removable. Thus, anything that passes through the raised access floor must be able to fit through an area smaller than that of a single panel. This may make replacement or installation of certain types of equipment impossible underneath the raised access floor.
Moreover, some raised access floor panel designs have multiple parts that are not well-assembled. In some instances, the raised access floor panel may be loaded in such a manner that assembled parts will tend to loosen over time, thereby compromising the design of the panel. In other instances, attachment of parts of the panel is excessively reliant upon relatively labor intensive and/or unpredictable attachment methods such as welding.
Still further, some raised access floor panel designs have structural parts that do not line up flush with each other on the top surface. Hence, a cover such as a vinyl plate must be installed on the top of the panel. Unfortunately, such covers may disrupt the panel's ability to serve as a grounding member to dissipate undesirable electric potential, such as static electricity.
Accordingly, it would be an advancement in the art to provide a raised access floor with panels that have a high strength-to-weight ratio, high impact strength, and a low tendency to disassemble under loading. It would also be an advancement in the art to provide raised access floor panels that can be fabricated with a relatively low fixed cost to permit easy adaptation of panel designs to provide panels of different sizes or panels with openings for component pass-through. Yet further, it would be an advancement in the art to provide a raised access floor panel that does not require the installation of a support framework or a nonconductive cover layer. Still further, it would be an advancement in the art to provide a raised access floor panel that is inexpensive and easy to manufacture.